Solar parabolic trough, receiver, tracker and drive system

ABSTRACT

This invention integrates the receiver as a support with improved performance and rigidity and eliminates moving fluidic components that increase the units overall reliability and lowers construction costs. The cable drive mount system provides foul weather operation coupled with a slip clutch for un anticipated loads. Integrating the sun tracker into the parabolic trough body eliminates the need for timing and calibration.

CROSS-REFERENCE TO RELATED APPLICATIONS

Provisional Patent 60/708172 Aug. 15, 2005

STATEMENT REGARDING FEDERALLY SPONORED RESEARCH OR DEVELOPMENT

Not applicable

REFERENCE TO A MICROFICHE APPENDIX

Not applicable

BACKGROUND OF THE INVENTION

Cost Reduced total System through Component Integration and StationaryFluidic Hoses

BRIEF SUMMARY OF THE INVENTION

The apparatus as depicted in FIG. 1.0 integrates the receiver tube as asupport for the parabolic trough and by bifurcating the fluid path inthe receiver tube, the fluidic hoses remain fixed with no movement whichreduces cost. Maintenance is minimized by stationary hoses. The drivemechanism is weight reduced by drum and cable integrated around thereceiver which gives the unit freeze protection and/or high temperatureprotection at low cost. The sun tracking electronics split the sun'sradiation with a fixed nose between the optical sensors just as thehuman nose between the eyes does. This feature removes calibration andmaintenance. The parabolic mirror is of silver on Mylar which reducesinitial cost and is repaired via a band-aid concept reducing initialcost and maintenance costs.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1. Solar Trough Assembly with integrated receiver mount and motordrive. FIG. 1. depicts a view of the trough built of a parabolic shapedaluminum with reflective silver membrane bonded to metal or plastic. Thelow cost and light weight Parabolic trough body rotates around theoutside of the receiver tube tracking the sun and focusing the suns rayson to a selective coating on the receiver tube. This implementationsupports polar mounting or east-west or north-south mountings. In thepolar mount the receiver tube will receive 20 percent more solarinsolation than in the conventional east-west or north-south mountingsduring the spring and summer months.

FIG. 2. Depicts the motor, drum and cable that drive the ParabolicTrough around the receiver tube. The cable is wrapped around the drum,which is attached to the trough body. The motor is attached to thereceiver tube.

FIG. 3. Depicts the receiver tube construction details. Incoming fluidsare routed around the center tube in a spiral motion to lengthen thefluids time to transverse the length of the bifurcated receiver tubewhere the fluid is returned inside the center tube and exits thestationary end of the receiver tube.

DETAILED DESCRIPTION OF THE INVENTION

This application integrates multiple components; tracker, motor drive,receiver and trough body that makeup the mirror and its support of aSolar Parabolic Trough into one entity to reduce costs and increaseperformance. Performance is increased by configuring the fluid path witha helix spiral that effectively triples the receiver tubes length oftime to receive energy while reducing the actual receiver length by twothirds.

Refer to FIG. 1 for the following description. Incoming heat transfermedium enters at number 1 to be heated. As the heated fluid is guided bynumber 3, the spiral looping path around the exit tube labeled as number2, effectively increases the length of travel for the heat transfermedium which increases time to absorb more energy than a straight pipe.At the end of the receiver tube labeled as 4, the heat transfer mediumis channeled into the center of the pipe for a direct and shorter timeto exit once the heat transfer medium is heated. The bifurcated channelthat has a longer time to transverse and a shorter time to return is themajor performance improvement of the receiver tube. The construction ofan inner tube number 2 with a rigid standoff number 3 and finallyencased with an outer tube number 5 makes for a more rigid receiver tubethat can be used as its own support and less sag so as to maintainoptical alignment with the trough body that rotates around the receivertube. The outer tube number 5 is mounted rigidly so no fluid path tubesrequire movement and eliminates swivel fluid joints.

Refer to FIG. 2 for the following description. The motor drive assemblyis mounted to the parabolic trough body by attaching to the receivertube number 1. The drum number Sis bolted to the body of the troughframe by number 6 holes in the drum number 5. A bearing surface number 7is dimensioned to fit the receiver tube number 1. For high temperatureoperation an insert can be fitted at number 7. The motor mount block 4is securely mounted to the receiver tube number 1. When the trackerprovides bi-directional movement to the motor, the motor's drum number3imparts motion to the cable number2 that is wrapped around the drumnumber 5. The drum number 5 floats of a bearing surface around thereceiver tube number 1. Motion to the trough body that is bolted to thedrum number 5, via the two bolts number 6. This embodiment of theapparatus allows for slippage on the motor drum number 3 whenoverloading should occur. No timing or alignment is required as thesystem is self recovering. Heating for the motor for cold weatherconditions is accomplished by scaling number 5 to conduct viacross-sectional area of number 5. High temperature operation isaccommodated by using an insulating material for number 5. By mountingthe sun tracker to the trough body alignment is maintained on thereceiver tube number 1.

1. Heat transfer is increased to the fixed receiver tube with it'sstationary fluid connections by sweeping the trough's concentrated lineof light focus around the exterior of the receiver tube every ⅓ of asecond with a rocking-chair action, which effectively increases thecross-sectional area for heat transfer;
 2. The receiver tube with aspiral fluid path increases the length of travel through the bifurcatedreceiver tube which increases the dwell time for the fluid to absorbheat and the short center tube rushes the heated fluid in as shortesttime out of the receiver tube;
 3. By attaching the motor or the motordrive system to the receiver tube, the motor can be heated for coldweather operation and isolated for extremely hot fluid operation via aninsulating ring, and where by the apparatus with integrated drive cable,capstan or motor eliminates timing and calibration issues as the unit isself recovering and has a slip clutch mechanism to protect againstunexpected loads.